1. Field of the Invention
The present invention is directed to an electrical speed sensor for motor vehicles and more particularly to the connecting drive between such an electrical speed sensor and a speedometer cable.
2. Prior Art
Conventional electrical speed sensors for motor vehicles have been used to generate electrical control signals which are proportional to the rotational speed of a vehicle wheel in order to control vehicle related systems such as an anti-skid braking control system. Such electrical speed sensors have also been used for indicating the rotational speed of the vehicle wheel on the vehicle speedometer. An example of such an arrangement is disclosed in U.S. Pat. No. 4,159,433 to Takayama et al, granted June 26, 1979. In the electrical speed sensor disclosed in this patent, a shaft is rotatably mounted in operative driving engagement with a vehicle transmission shaft. A rotor is mounted on the shaft for generating an electrical signal and the rotatable core of the speedometer cable is connected directly to one end of the rotatable shaft. Since the electrical speed sensor is usually located in narrow, confined spaces close to the vehicle body frame, it is often necessary to bend the speedometer cable very sharply adjacent its connection to the rotatable shaft of the electrical speed sensor. As a result of such a sharp curvature, the cable core may not be rotated smoothly within the cable with a resultant erroneous indication of the vehicle speed on the vehicle speedometer.